Research Article

An Effective Color Quantization Method Using Octree-Based Self-Organizing Maps

Algorithm 1

Learning algorithm of octree-based SOM color quantization.
Require: image as a vector of pixels, number of neurons .
Ensure: weight
  Build octree on image and prune the nodes until nodes remain.
   value of pruned nodes
  loop counter
      generate subset of training pixels
      number of training data
     adjusted learning rate for winner node
    for    to    do
      Determine the winner node
      Update weight of the winner and its neighbors
    end for
  until weights converged